Google has changed the way it's counting devices running particular Android versions. "Beginning in April, 2013, these charts are now built using data collected from each device when the user visits the Google Play Store. Previously, the data was collected when the device simply checked-in to Google servers. We believe the new data more accurately reflects those users who are most engaged in the Android and Google Play ecosystem." The change does actually make sense - reflecting the kind of usage developers are interested in - but the fact that this also makes Jelly Bean jump from 16% to 25% surely played an important role here too. This means that Ice Cream Sandwich and later now account for about 54% of Android devices in use.

What more information do those numbers give us than what the OS statistics of active Android users do?

I can understand Google's viewpoint. Any Android 2.x phone out there, used as a dumbphone, is uninteresting to the Android ecosystem. For a developer, there is no use in targetting a certain "strain" of "dominant" Android 2.x, if the users of that version never show up in the Play Store. To move the the App ecosystem forward, developers can't maintain compatibility with the lowest (and as it turns out, not the common) denominator forever.

The new numbers seem to suggest that the lowest common denominator is API level 10. Anything below that is too small to invest effort in.

Yes, that is bad news for anybody, active in the playstore, on a phone that runs any version of Android below 2.3.3. Better get an ICS phone soon, as newer Apps might not work anymore. (Or go custom rom with a higher API level).